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Problem using ndrange with Intel Graphics

QM
Employee
497 Views

Hi,

 

I am using DPC++ to enable parallelization for my code. Using sycl::ndrange<1>{N, worker_number} works totally fine when run on CPU (using sycl::host_selector{}). However, when I switch to Intel graphics by using sycl::default_selector{}, the errors are caused by the use of ndrange ( switch to range approach works). Does anybody know what's wrong with it? 

 

Here is details of my dpcpp version: 

-Intel(R) oneAPI DPC++/C++ Compiler 2022.0.0 (2022.0.0.20211123)

-Target: x86_64-pc-windows-msvc

-Thread model: posix

 

Thanks,

Q

0 Kudos
6 Replies
QM
Employee
484 Views

I have posted this question to Intel OneAPI DPC++ forum as I believe it's more related there. But if anybody know the issue, please let me know.  Thank you.

Ben_A_Intel
Employee
473 Views

Hi, what are your nd_range dimensions?  Specifically, what is the value of worker_number in the code snip above?

GPUs (and other types of accelerators) have limits on the maximum size of the local range (AKA "work-group size"), and if you are exceeding the device maximum you will get an error.

If you're sure that the value of worker_number is supported by your GPU can you please send additional information about the error you are seeing?  Thanks!

QM
Employee
420 Views

Hi Ben,

 

Thanks for your reply,  local range is previously set at 64, then I changed it to 1, but still does not work. The error message is blank, yeah funny, but honestly, blank. Switching to sycl::host_selector{} and it works perfectly.

 

Regards,

Ben_A_Intel
Employee
382 Views

Can you run your test with oneTrace enabled, especially with the CallLogging option ("-c")?  This might provide more hints why the error is occurring.

https://github.com/intel/pti-gpu/tree/master/tools/onetrace

If you can send the exact error you are seeing this will help also.  Thanks!

SantoshY_Intel
Moderator
339 Views

Hi,

 

We have not heard back from you. As suggested by @Ben_A_Intel , could you please try running your test with oneTrace and send the exact error you are seeing?

 

Thanks & Regards,

Santosh

 

SantoshY_Intel
Moderator
302 Views

Hi,


We have not heard back from you. This thread will no longer be monitored by Intel. If you need further assistance, please post a new question.


Thanks & Regards,

Santosh


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